Differential antigen expression between human eccrine sweat glands and hair follicles/pilosebaceous units

Eccrine sweat glands and hair follicles are two primary skin appendages that serve different functions. Although the two appendages exhibit unique morphological patterns in adults, it is difficult to distinguish them morphologically in the early stages of development and regeneration. To research and compare the development, differentiation and regeneration between eccrine sweat glands and hair follicles/pilosebaceous units, specific antigen markers must be found first. Human skin samples were fixed, paraffin-embedded, and cut. The expression of K5, K7, K8, K14, K27, K31, K73, AE13, α-smooth muscle actin (α-SMA), epithelial membrane antigen (EMA), carcinoembryonic antigen (CEA), Na⁺/K⁺-ATPase α and Na+-K⁺-2Cl cotransporter 1 (NKCC1) in eccrine sweat glands, hair follicles and sebaceous glands was detected by immunofluorescence staining. The results showed that eccrine sweat glands expressed K5, K7, K8, K14, K31, α-SMA, CEA, EMA, Na⁺/K⁺-ATPase α and NKCC1, but did not express K27, K73 or K31. Hair follicles expressed K5, K8, K14, K27, K31, K73, α-SMA and AE13, but did not express K7, CEA, Na⁺/K⁺-ATPase α or NKCC1. Sebaceous glands expressed K5, K14, K73, and EMA, but did not express K7, K8, K31, α-SMA, CEA, EMA, Na⁺/K⁺-ATPase α or NKCC1. We concluded that K7, CEA, Na⁺/K⁺-ATPase and NKCC1 can be used as specific markers for eccrine sweat glands, K27 and AE13 can be used as specific markers for hair follicles, and K73 can be used as a specific marker for pilosebaceous unit. These specific markers may contribute to differentiate between eccrine sweat glands and hair follicle/pilosebaceous units.